Can anyone design an RFID detector or scanner ? Is there such a thing?

I was thinking that with the invention many, many moons ago by Hitachi of Smart Dust - dust-sized RFID chips, it may be a good idea to develop an electronic gizmo to detect these RFID items and to locate them wherever they are placed.

What we really need is a 'scanner' which scans all the frequencies looking for a chirrup answer from the chip. It would not have to be that expensive maybe although I dont know what is involved, but it would be nice to have a DIY design which folks who are reasonably adept at soldering could make for themselves. Possibly a version which scans a room and another with a kind-of direction finder which pinpoints the RFID chip in the room or on the body.

Anyone good at this kind off design of electronic circuits and directional aerials?

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I know that the small size of RFID chips is nothing new and there have been a few threads highlighting how dangerous it is to our freedom to have such small potentially identifying tags around, but this article from Oct 2012 sums it up nicely.

In case you want to read more, here are a number of articles by FederalJack which addess different aspects (although they are from 3 or 4 years ago now)

From MedicsIndex.net

Smart-dust: Hitachi Develops World's Smallest RFID Chip. Nicknamed "Powder" or "Dust", the surface area of the new chips is a quarter of the original 0.3 x 0.3 mm, 60µm-thick chip developed by Hitachi in 2003. And this RFID chip is only one-eighth the width of the previous model.
-- Hitachi expects this tiny size will open the way to new applications for wireless RFID chips. The RFID "powder" can be incorporated into thin paper, such as currency, creating so-called "bugged" money.

The RFID Loc8tor can identify special RFID tags from a distance of up to 183 meters (600 feet), and the RFID chips have GPS capabilities.

"By taking advantage of the merits of compactness, high authenticity and wireless communication, and combining it with Internet technology, the µ-Chip may be utilized in a broad range of applications such as security, transportation, amusement, traceability and logistics" – said Hitachi engineers who worked on the project.

Wikipedia on Smart Dust & Smart Specks

from 2001 !! an article on Smart Dust by Berkeley Robotics department Some amazing stuff done even then.
from 2007 Another old one

Yes it can be done. It's actually low tech.

I found easy to build instructions on this link:

www.instructables.com...

I don't know if it will detect the smaller ones, but it might be worth a try. Maybe Hitachi makes a detector for the small chips?

a reply to: qmantoo

Interesting, so you are asking for a D.I.Y. RFID detector and reader or just detector? With things you could buy at Radio Shack or a part or two off E-bay? That works kind of like a bug detector?

I think the best design would be to have a detector that buzzes louder the closer you get to a chip - it could come with an attachment to read the chip. What do you think O.P.?

I see other people have linked to something - I will have to check it out.

Yes, a detector, there are plenty of readers around - so something like direction finding equipment for radio transmitters or hidden bug finding equipment. The actual data or number in these tags is not so important as the finding whether there is one in the area. With these things being so small, we need to know -

a) if there are any in the room
b) where they are

or
c) if we have one in our body
d) where it has lodged

The thought I had is that it could be like a radio scanner which sweeps the frequencies for radio transmissions and then once you know what you are dealing with, then you could use a more sensitive detector to find it in room/body/etc

Depending on where you are in the world there are different licensed radio frequencies Europe, USA, etc There are quite a few bands used for these things and then within the bands I think you can use different frequencies so they dont interfere with each other.

I am sure it is more complicated than that but a proof-of-concept device might be interesting.

Edit - It seems like the Instructable is an RFID READER detector as it picks up the energy transmitted by the reader (the reader needs to do this to allow the tags to be activated). If my understanding is correct, it only detects the reader and not the tag itself.

We would need a fairly powerful transmitter coil to energise any tags in the room and cause them to chirrup back to the device we would be using. Then if we wanted to sweep other frequency tags we would have to change the size of the coil so that it resonated in tune with the correct frequency of the tag we were searching for. (I dont know much about electronics as you can tell, but I think this is right. Someone correct me please if wrong)

Maybe Hitachi makes a detector for the small chips?

I suspect that they only supply readers and they probably assume you know where you put the tags. Readers can pick up tags from a fair distance depending on the transmitted power and whether the tags are passive, semi-passive or active ones with batteries in them. One of the links I gave in the original post mentions 300ft I think but that may be for active tags.

The read range of passive tags depends on many factors: the frequency of operation, the power of the reader, interference from metal objects or other RF devices. In general, low-frequency tags are read from a foot or less. High frequency tags are read from about three feet and UHF tags are read from 10 to 20 feet. Active RFID tags, on the other hand, offer very long read ranges -- up to 300 feet under optimal conditions.

for passive Hitachi RFIDs

it can operate at temperatures of -40 degrees to +85 degrees Celsius (-40 degrees to +185 degrees Fahrenheit—make it unique, he says, as does the ability of the tag's built-in antenna to capacitively couple with a booster antenna (or other metallic object), thereby extending read range to 4 or 5 meters (13.1 feet to 16.4 feet).